8.4. Chemical Reactions and Energy http://www.ck12.org
- What happens to the energy that is absorbed in an endothermic reaction?
- In an exothermic reaction, which has more stored chemical energy: the reactants or the products?
- Define activation energy.
- List four factors that affect the rates of chemical reactions.
Apply Concepts
- Suppose you put a whole antacid tablet in one glass of water and a crushed antacid tablet in another glass
containing the same amount of water. Both tablets would start reacting and producing bubbles of gas. Use
lesson concepts to predict which tablet would stop producing bubbles first. Explain your prediction. Then,
with the permission of an adult, do the activity. Do your results agree with your prediction? - Sketch a simple graph to show how energy changes in an exothermic reaction. Include activation energy in
your graph.
Think Critically
- Compare and contrast endothermic and exothermic chemical reactions.
Points to Consider
You read in this chapter that most fuels contain carbon. In the next chapter, "Chemistry of Carbon," you will learn
much more about carbon.
- What do you already know about carbon?
- Based on carbon’s position in the periodic table, predict how it reacts and the type of bonds it forms.